Abortion Increases Risk of Subsequent Premature Birth

By Randall K. O'Bannon, Ph.D.,NRL-ETF Director of Education & Research

In 2003, when pro-life Ob-Gyn Byron Calhoun and researcher Brent Rooney published their summary of 49 studies that showed having an abortion increased the risk of subsequent prematurity in the Journal of American Physicians and Surgeons [1] the world didn't give the subject much attention. Now, with the publication of a major study coming out of France in the British Journal of Obstetrics and Gynecology[2] solidly confirming the link between abortion and subsequent premature births, the evidence and the implications will be harder to ignore.

The study, titled "Previous induced abortions and the risk of very preterm delivery: results of the EPIPAGE study," covered about one-third of all premature births occurring in France in 1997. Dr. Caroline Moreau of INSERM, France's National Institute of Health and Medical Research, and colleagues examined the records for 1,943 very preterm births (born between 22 and 32 weeks), 276 moderately preterm births (born at 33-34 weeks), and a comparison group of 618 full-term births.

The conclusion the French research team reached is that women with a history of induced abortion had a 50% higher risk of having a very preterm delivery than women who had not aborted. The risk was 70% higher for delivering a baby at 22 to 27 weeks gestation, a category which researchers call "extremely preterm deliveries." (This can be confusing unless you understand that the "extremely preterm birth" category is a subset of the larger "very preterm birth" category: 22-32 weeks.)

The idea that abortion might have an impact on future pregnancies is logical enough. Abortion involves not simply the destruction of the unborn child, but an aggressive assault on the woman's reproductive organs.

Any injury, even if undetectable at the time of the abortion, might have consequences when that woman becomes pregnant in the future. In other words, more than one child may die from the original abortion.

Results were even more striking when researchers looked at the association between abortion and specific causes of subsequent very preterm delivery (22-32 weeks).

There was no observable connection between having an abortion and having a subsequent very preterm delivery that is due to high blood pressure, a common cause of prematurity. However, there was a substantial increased risk of premature birth causes that could conceivably be tied to infections or injuries brought on by what the authors refer to as the "mechanical processes" of abortion.

For example, the study showed a 40% increased risk of a very premature birth (22-32 weeks) caused by placental abruption (separation of the placenta from the uterine wall, accompanied by hemorrhage) and 140% increased risk of very premature birth tied to placenta previa (in which the pregnancy implants low in the uterus, partially or completely covering the cervical opening, which can involve bleeding in the third trimester).

The increased risk of subsequent extremely preterm births (22 to 27 weeks) for women who have had an abortion was even greater. Risk of placental abruption in these cases was 50% greater, while the risk of placenta previa was 310% higher!

There were also significant increases in risk (70%-120%) associated with other common causes of preterm birth, such as fetal growth restriction, prematurely ruptured membranes, and the early onset of labor.

The significance of these findings cannot be overstated. Babies have survived and thrived even when born as early as 22 or 23 weeks old, but generally speaking, the earlier the baby is born, the greater the risk to the life and health of both mother and child.

The researchers say that their findings, along with those of similar studies, "all suggest that induced abortion could produce cervical and uterine abnormalities, responsible for an increased risk of subsequent preterm delivery."

It has been speculated elsewhere that damage to the endometrium during aggressive curettage may prevent the embryo from implanting in its normal place in the upper uterine wall, leading to placenta previa or placental abruption.

Researchers speculate that forced or mechanical dilation of the cervix in abortion may lead to cervical incompetence (so that the uterus fails to hold the child in place), which may increase the risk of upper genital tract infections. Generally, the authors say, abortion may bring about the "revival of local infections processes caused by surgery," itself believed to be a risk factor for premature rupture of the membranes.

Pro-lifers have long made the point that every abortion has at least two victims - - the innocent child, who loses his or her life, and the mother, who is often emotionally scarred and possibly physically damaged. This new evidence demonstrates that abortion may not only claim those immediate victims, but may reach into the future to strike a woman's later offspring.

Turns out that Calhoun and Rooney were really onto something after all.

NOTES:1. See our report "Abortion Linked to Subsequent Premature Births" on Calhoun and Rooney's article in the July 2003 NRL News.2. Caroline Moreau, et al., "Previous induced abortions and the risk of very preterm delivery: results of the EPIPAGE study," British Journal of Obstetrics and Gynecology, 112 (April 2005): 430-37.

First published in National Right to Life News. Reprinted in Action Life News summer 2005, with permission